Punch with guide cooperating with a pattern fix on a work piece



Sept. 19, 1961 L. FOSKETT 3,000,249

PUNCH w GUIDE COOPERATING WITH A PATTERN FIX 0 WORK PIECE FiledOct. 1956 INVENTOR.

MA Y/Vfi/FD A Fax: 7' 7- BY WW amid/.01 W1 United States Patent 6 3,000,249 PUNCH WITH GUIDE COOPERATING WITH A PAITERY FIX ON A WORK PIECE Maynard L. Foskett, Kalamazoo, Mich., assignor to Clarage Fan Company, Kalamazoo, Mich, a corporation 'of Michigan Filed Oct. 1, 1956, Ser. No. 613,058 2 Claims. (Cl. 83-249) This invention relates in general to a guide mechanism or centering device for a punch and die assembly and, more particularly, to a type of such mechanism whereby a point or position on a workpiece may be accurately and quickly located with respect to the punch, and whereby the punch and die assembly can be quickly removed for the purpose of changing punch sizes.

Persons acquainted with the operation of equipment used to punch openings through sheet materials have long been aware of the fact that a substantial amount of time is required to prepare a conventional machine, such as a press brake, for a punching operation. Where only a few pieces are to receive a punching operation, the per piece cost is severely increased by the set up time.

In general, it has been found that jobs involving punching operations fall into three time categories, depending largely upon the number of work pieces to be punched in an identical manner. Where the operation involves a relatively large number of work pieces it is advantageous to set up a machine, such as a press brake, with guide elements so that each work piece is punched in exactly the same place, when positioned against said elements. No markings or other treatment are required with respect to the individual workpieces so long as they have the same relative outside dimensions or configurations at the points where they engage said elements. In this case, preparation of the machine for the punching operation generally requires a considerable amount of time. However, because of the relatively large number of pieces to be punched, the gross per piece time, which equals the preparation time plus the total punching time divided by the number of pieces punched, is relatively low. Where smaller groups of pieces are involved, it then becomes advantageous to. eliminate the preparation time because it produces a relatively high, gross per piece time. This can be accomplished by providing some type of template which is placed on each work piece to be punched, and whereby the punch is guided into proper position with respect to the work piece. In the case of very small groups of work pieces each sheet is normally properly marked as by means of a prick punch at the layout floor, after which the punch on the punch machine must be carefully directed by such means as have been presently available, into position with the prick punch mark or other locating mark on the work piece.

This invention is particularly directed to reducingsubstantially the amount of time lost in setting up or preparing present punching equipment, and thereby reducing the gross per piece time, for the relatively small jobs found in the last two categories.

Where only a few work pieces are being punched, resort has been made also to the type of punch press wherein the punch is manually moved into a position of approximately alignment with the work piece, or into a position of engagement with a template mounted upon the work piece, after which the punching operation is performed. Operation of this type of machine ordinarily necessitates that the operator lower the punch with one hand While trying to move the work piece into proper alignment position with respect to said punch with the other hand. Particularly Where large and heavy sheets ice 2 of material are involved, this arrangement is not only difficult but actually dangerous to the. operator.

Further, it is usually very difiicult and time consuming to change the punch size in a machine having manually operated, punch aligning mechanism of this general type. Accordingly, particularly Where a template is used and only one such machine is available for the job, the operator is faced with the difficult choice of transferring the template to each of several work sheets as the same size of opening is punched therein, or change the punch and complete each sheet before removing the template therefrom, either of which requires a considerable amount of time. A third and very costly alternative is to tie up a group of these machines, each one being set for a different punch size, while a relatively small number of pieces are being processed.

In attempting to provide mechanism for overcoming the above mentioned problems, a principal objective has been the provision of guide mechanism or a centering device for a punch and die assembly, permitting quick and easy removal of the punch assembly from the punch actuating mechanism, such as a press brake, permitting unobstructed observation of the punch guiding mechanism with respect to the work piece at all times, permitting the operator to employ both hands in moving the work piecev for the purpose of aligning the punch with respect to a point or position on the work piece, and permitting speedier and more accurate results than are possible with previous equipment for the same or similar purposes.

A further object of this invention has been the provision of a centering device, as. aforesaid, which is adaptable to use either with or without a template, which prd vides its own stripping action, which is easily and quickly adaptable to use with any type of conventional punch press presently in ordinary use and which can. be. assembled and operated, by any person capable of handling or operating a conventional punch press.

A further object of this invention has been the provision of a centering device, as aforesaid, whichis relatively simple and inexpensive to fabricate, which is. relatively simple to maintain, and'which will give to certain types of machines, such as the press brake, a versatility in op.- eration unavailable heretofore.

Other objects and. purposes of this invention will become apparent to persons familiar with this type of equipment upon reading the following specification and. examining the accompanying drawings, in which:

FIGURE 1 is an enlarged sectional view of the punch and die assembly to which the invention relates.

FIGURE 2 is an enlarged fragment of FIGURE 1 with the parts thereof shown in a different operating position.

For the purpose of convenience in description, the terms upper, lower,. and derivatives thereof, will have reference to. the punchand. die assembly, and parts associated therewith in their normal position of operation as appearing in FIGURE 1 as well as to corresponding directions in any other position of operation. The terms inner, outer, and derivatives thereof, will have reference to the geometric center of said punch and die assembly and parts associated therewith.

As shown in FIGURES 1 and 2, the punch and die assembly 51 is comprised of a die 52 supported on an arm 17 which is mounted on the bed of a conventional press brake (not shown). The sleeve 53 is supported on an arm 15 located above arm 14. The lower end 54 of sleeve 53 is carefully machined for snugly slidable reception into a corresponding opening 55 in a template 56 which is mounted upon a work piece 21 by means such as a C-clamp 57 or other fastening device of any convenient type. Furthermore, since the sleeve 53 serves to locate the punch with respect to a workpiece, said sleeve is not V 3 resiliently supported. The punch 58 has a head 59, a shoulder 61 limiting its downward movement with respect to the sleeve 53, and a punch tip 62. The head 59 is engageableby the ram 19 of a press brake (not shown). The template 56 and cooperating lower end 54 of the sleeve 53 serve to locate the punch 58 with respect to a position on the work piece 21'disposed between the die 52 and said punch 58. .A spiral, punch spring 63 encircles'the punch 58 between the punch head 59 and the sleeve 53. The sleeve 53 is slidably disposed. within an appropriate opening 64 in' means, such as the upper arm 15 of a C-shaped support device (not shown in its entirety) having a lower arm 17 upon which the die 52 may be mounted.

Before the assembly 51 is utilized, it is first necessary, to mount the template 56 upon the work piece 21. The sleeve 53 is then raised upwardly away from the die 52 and'the work piece 21, with the template thereon, is placed upon the die 52 below the punch 58, after which the sleeve 53 is released and it drops to the upper surface of the template 56. The Work piece 21 is now moved, along with the template 56 mounted thereon, until the lower end 54 of the sleeve 53 drops into the proper opening 55 in the template 56, which indicates that the punch 58 is now positively and accurately positioned for the punching operation. Thus, actuation of means such as said press ram 19 (FIGURE 1) will cause the punch 58 to move downwardly until the punch tip 62 thereof penedates the work piece 21 (FIGURE 2) while at the same time compressing the punch spring 63. The return upward movement of the punch 58 with respect to the sleeve support structure having vertically spaced upper and lower support members, said upper support member having a cylindrical sleeve opening extending therethrough and toward the lower support member; a sleeve slidably and snugly received into said sleeve opening for axial movement toward and away from said lower support member, said sleeve having an integral, radially outwardly extending flange ,near its upper end engageable with said upper member'adjacent the upper end of the sleeve opening for supporting said sleeve upon said upper support member, said sleeve having a coaxial punch guide opening therethrough, the lower end of said sleeve extending below said upper support member and being slidably and snugly 53 is effected by the punch spring 63, as the ram- 19 7 moves upwardly, thereby automatically shipping the work piece from said punch tip 62. The sleeve 53 can then be manually raised to disengage it from the template opening 55 for the purpose of either moving the work piece 21 to effect engagement of'said sleeve 53 with another template opening 55, or removing the template and work piece completely from between the punch and die.

The guide or centering device disclosed herein with respect to the punch and die assembly 51 is capable of quick and easy removal from its support means, such as the arms 15 and 17, and replacement with a similar punch and die assembly of a difierent size. Although one embodiment of the invention has been described in detail hereinabove for illustrative purposes, it will be recognized that other variations .or modifications thereof which do not depart materially from the scope of such description are fully contemplated unless specifically stated to the contrary in the appended claims.

I claim:

1. A punch and die assembly for providing a plurality of openings through a substantially flat work piece, comprising: a template having a plurality of guide openings, said guide openings being of predetermined sizes and 'being located in predetermined positions with respect to each other; means for removably clamping the template upon the work piece with said guide openings located in selected positions over the workpiece; a punch and die receivable'into one of the guide openings in said template when said flange is adjacent said upper support member; at least one punch having a work engaging end capable of producing the desired openings through said work piece when said sleeve is 'in said guide openings, said punch having an' elongated body portion slidably and snugly disposed within said punch guide opening for movement lengthwise of the central axis thereof, said punch having a radially outwardly extending flange spaced from the work engaging end a 7 distance substantially greater than the axial length of said sleeve;'resiliently flexible means disposed between the flange on said sleeve and the flange on said punch, said flexible means normally holding the work engaging end of said punch above the lower end of said sleeve and resiliently resisting movement of said punch through said sleeve toward the lower support member; at least one die corresponding to each said punch and securable upon said lower support member in axial. alignment with said sleeve opening in the upper support member, said die having an upper surface conforming with the lower side of the work piece adjacent a guide opening in said template, said die having a punch opening penetrating said upper die surface for snug slidable reception of the work engaging end of said punch, whereby the work piece can rest upon the upper surface of the die and be held thereagainst by the lower end of said sleeve which enters a guide opening .in the smaller cross sectional area than the portion of said punch immediately above said lower portion.

References Cited in the file of this patent UNITED STATES PATENTS 154,161 Vankirk Aug. 18, 1874 804,795 Cummings Nov. 14, 1905 1,653,152 Daley Dec. 20; 1927 2,307,617 Byaun Jan. 5, 1943 2,427,409 Kirsch Sept. 16, 1947 2,839,306 Bayless June 17, 1958 

